enum
{
  LED_GREEN = 0,
  LED_BLUE,
  LED_ORANGE,
  LED_RED,

  LED_MAX
};

const byte leds[4] = {12, 10, 8, 7};

void setup()
{
  Serial.begin(9600);

  for (int i = 0; i < LED_MAX; ++i)
    pinMode(leds[i],  OUTPUT);
}

void loop()
{
  Serial.print("Hello World !\n");
  all_lights_on();
  delay(200);
  all_lights_off();
  delay(1000);
}


void all_lights_on()
{
  for (int i = 0; i < LED_MAX; ++i)
    digitalWrite(leds[i], HIGH);
}

void all_lights_off()
{
  for (int i = 0; i < LED_MAX; ++i)
    digitalWrite(leds[i], LOW);
}
